Makoto Tadokoro

Faculty of Science, Tokyo University of Science

Research AreasSupramolecular Coordination Chemistry, Water Cluster Science, Molecular Conductor
Participating Group (2018-2019)

Study on Nanoporous Molecular Crystals and PCET Conductive Mechanism by Using Hydrogen bonding Metal Complexes

Low Barrier Hydrogen Bond, Proton-Coupled Electron Transfer, Nanoporous Crystal, Mixed-Valence State, Soft Crystal, Molecular Conductor, Metal Complex
Co-Researcher: Hajime Kamebuchi (Faculty of Science, Tokyo University of Science, Assistant Professor)
Co-Researcher: You Suzuki (Faculty of Science, Tokyo University of Science, Post Doctor)
Co-Researcher: Kenji Yamane (Faculty of Science, Tokyo University of Science, Post Doctor)
Co-Researcher: Daiki Kan (Faculty of Science, Tokyo University of Science, Post Doctor)
Co-Researcher: Daiki Nagatome (Faculty of Science, Tokyo University of Science, Post Doctor)

Research Outline

In a strong hydrogen bond, the low-barrier hydrogen bond (LBHB) with a low transfer-barrier energy for the proton is often observed in a biological molecule as one of hydrogen-bonds with the same pH values between hydrogen bonding donors and acceptors.

LBHB Double-Well Potential Model

The transition metal complexes connected with LBHB would be easily stabilized mixed-valence states by a H-bonding proton transfer,

Proton-Assisted Electron Trasfer Mechanism (Honeycomb Sheet Mixed-Valence Type)

switched by the electrochemical redox reaction.

Solid-State CV of H-bonding Mixed-Valency Crystals

While, each localized state of the PCET (proton-coupled electron transfer) reaction observed through an isolated molecule are affected by solvation in solution. However, in crystal without solvation, the mixed-valance metal complexes connected with LBHB are often observed a PAET (proton-assisted electron transfer) reaction simultaneously transferred both protons and electrons, which has been clarified on a physical property continuously fluctuated a proton and electron. Therefore, we would like to study on evolution of a functional material and elucidation of the mechanism of a PAET crystal. (1) Elucidation of PAET Mechanism by Dimer Complex Crystal with LBHB (2) Study on Molecular Conductor of Honeycomb Sheet Crystal Connected with LBHB (3) Development of PAET Conductor Controlled the Multi-dimensionality. As a result, we would like to elucidate a new molecular material coupled with a proton transfer and electron transfer without solvation.


Academic papers/reviewed


  1. "Slow Dynamics of Premelting Water Molecules Confined to Hydrophilic Nanoporous Space" Y. Ohata, H. Kamebuchi, K. Watanabe, T. Kouchi, Y. Suzuki, T. Imaizumi, T. Sugaya, M. Mizuno, and M. Tadokoro, Chem. Select, 4, 6627-6633 (2019).
  2. "Synthesis and electrochromic behavior of a multielectron redox-active N-heteroheptacenequinone" K. Isoda, M. Matsuzaka, T. Sugaya, T. Yasuda and M. Tadokoro, Org. Biomol. Chem., 17, 7884-7890 (2019). プレリリース・カバーピクチャー
  3. "Proton Conduction Inhibited by Xe Hydrates in the Water Nanotube of the Molecular Porous Crystal {{[RuIII(H2bim)3](TMA)}2·mH2O}n" H. Matsui, T. Sasaki, and M. Tadokoro, J. Phys. Chem.C, 123, 20413-20419 (2019).
  4. "Photo‐Modification of Melanin by a Mid‐infrared Free‐electron Laser" T. Kawasaki, A. Sato, Y. Tominaga, Y. Suzuki, T. Oyama, M. Tadokoro, K. Tsukiyama, K. Nokihara, H. Zen, Photochemistry and Photobiology, 95, 946-950 (2019).
  5. "Dynamic Water Nanotube Cluster Stabilized in Molecule-Based Hydrophilic Nanoporous Crystal with New Organic Spacers" Y. Ohata, K. Takaya, T. Sugaya, H. Kamebuchi, M. Tadokoro, Bull. Chem. Soc. Jap., 2019, 92, 655-660.
  6. "Evidence of Proton-Coupled Mixed-Valency by Electrochemical Behavior on Transition Metal Complex Dimers Bridged by two Ag+ Ions" M. Tadokoro, K. Isogai, S. Harada, T. Kouchi, T. Yamane, T. Sugaya, H. Kamebuchi, Dalton Trans., 2018, 48, 535-548.

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